The present invention relates to a motor-vehicle door latch. More particularly this invention concerns such a latch that is connected to locking and latching elements of a motor-vehicle door.
A standard motor-vehicle door has inside and outside panels carrying outside and inside handles serving for unlatching the door and outside and inside locking elements for locking and unlocking the door. The inside locking element is typically a button or lever and the outside locking element is normally only provided on the front doors and comprises a lock cylinder and/or a keypad. A motor-vehicle latch in the door holds latching and locking mechanism operated by the handles and actuators and normally engageable about a bolt mounted on the door post to secure the door shut. More specifically this mechanism normally includes actuating levers connected to the inside and outside handles, a release lever operated by the inside and, if provided, outside locking elements, and a retaining member or fork that fits around the bolt in a latched position.
As described in U.S. Pat. No. 4,735,447 the latch has an outer housing part formed with a recess in which the bolt is receivable and provided with a latch fork pivotal between a holding position securing the bolt in the recess and a freeing position permitting the bolt to enter and exit the recess and with a latch pawl pivotal on the outer housing part into and out of a position retaining the fork in the holding position. A middle housing part lying on the outer housing part carries releasing mechanism connected to the pawl for moving same into and out of its position retaining the fork in the locked position, locking mechanism connected to the releasing mechanism for preventing same from operating the pawl to release the fork, and locking and opening levers respectively connected to the locking and releasing mechanisms and connectable respectively to the outside door locking element and outside door handle for operating the respective mechanisms. An inner housing part lying on the middle housing part carries respective locking and opening links connected to the inside latching and locking elements and a servomotor connected to the locking mechanism for operating same and preventing operation of the releasing mechanism by the opening link and lever. Fasteners secure the parts to contain the mechanisms and servomotor.
In such a system the various levers project from the respective housing parts through relatively large openings that permit them to make the necessary movements. Even the connection to the bowden cable that normally extends to the inside latching element is a relatively large hole.
Thus a significant problem with this type of latch is that dust and water can get into the latch mechanism relatively easily. This obviously leads to premature wear and failure of the latch. In addition the relatively large openings through which the actuating levers and connecting links of the latch mechanism pass make it possible to break into the vehicle by gaining access to this mechanism through these holes in the latch housing.
In another system described in U.S. Pat. No. 5,752,346 a motor-vehicle door has generally upright inside and outside panels, a window frame above the panels, a track extending vertically between the panels into the frame, and a window glass vertically displaceable in the track between the panels. A latch assembly has a holder, an outside door handle in the holder, a door latch on an edge of the door between the panels, and a connecting housing between the panels and having an upper part fixed to the door latch and a U-section lower part fixed to and carrying the holder for the outside handle with the handle on the outside door panel. A link rod extends between the outside door handle and the door latch and is laterally enclosed by the U-section lower part.
Such an arrangement offers considerable security and protection from the elements. It is however quite complex and expensive to manufacture.
It is therefore an object of the present invention to provide an improved motor-vehicle door latch.
Another object is the provision of such an improved motor-vehicle door latch which overcomes the above-given disadvantages, that is which is better protected against the elements, whose mechanism is better protected against inappropriate actuation, and which is of simple and inexpensive construction.
A latch according to the invention is mounted between the inside and outside of a motor-vehicle door provided with a plurality of actuating elements and respective links extending from the elements and each having a respective movable part. The latch has latching and locking mechanism, a closed housing enclosing the mechanism and formed with respective openings receiving free ends of the links, and seals in the openings engaged hermetically around the link free ends. The free ends are connected inside the housing to the mechanism.
In this manner the mechanism, at least the locking and actuating parts if not the actual latching element, that is the fork and its pawl, are completely protected inside the housing. The lack of gaps around the links prevents water or dust from outside from getting into the housing and also makes unwanted manipulation of the latch through these openings impossible.
According to the invention the housing includes a pair of housing parts that are hermetically joined to each other and the mechanism includes locking and latching elements received in the respective parts. The holes are all formed in one of the parts.
At least one of the links is a bowden cable that includes a flexible cable sheath engaged in the respective opening and engaged by the respective seal and a core longitudinally displaceable in the sheath and connected to the mechanism. In this case the seal engaging the sheath is an O-ring. The sheath can also be encapsulated or integrated right into the one housing part. Thus when assembling the door all that is necessary is to connect the outer free ends of the links to the various parts, such as the door handles, lock button, and/or lock cylinder, as the latch is delivered to the factory with the links already attached and integrated with the housing.
In accordance with the invention at least one of the links is rotatable and the respective free end includes a body rotatable in the housing and engaged by the respective seal. The body is rotatable about a respective axis and has radially outwardly projecting teeth. The mechanism includes a lever having a toothed end meshing with the teeth. More particularly, the body is a sleeve formed with a central throughgoing bore and the respective link has a head complementarily engageable in the bore. The housing is formed with a throughgoing passage in which the body is fitted and rotatable about its axis. This passage has an inner surface in which is set an O-ring constituting the respective seal.